The present invention relates to a mechanically controllable brake booster for hydraulic brake systems of automotive vehicles comprising a pressure casing adapted to be attached to a carrier and including at least one piston or movable wall arranged therein which subdivides the pressure casing into a low-pressure chamber and a working chamber and acts via connecting members and a reaction device on a push rod leading to an element receiving the boosted force, preferably a master brake cylinder, adapted to be fastened to the pressure casing, and including further a control rod adapted to be operatively connected to the reaction device to actuate a valve controlling the pressure in the working chamber.
A brake booster of this type is disclosed in copending U.S. application of J. Belart and F. Wienecke, Ser. No. 61,113, filed July 26, 1979, assigned to the same assignee as the present application. In this brake booster, for the purpose of relieving the load or force applied to the walls of the pressure casing and achieving a reduction in weight, there is provided a reinforcement tube extending axially through the pressure casing and carrying at its one end the force-receiving element while its other end serves to secure the brake booster to a carrier member, for instance, the splash-board of a motor vehicle. The piston or movable wall is guided on the outer circumference of the reinforcement tube and carries connecting members extending through slots into the interior of the reinforcement tube, with a control housing accommodating the reaction device and the valve being fastened to the end of the connecting members.